Jack Bauer has won the prologue time trial at the Herald Sun Tour, giving round one to Garmin-Sharp in their duel with Orica-GreenEDGE.

The New Zealander beat compatriot Tom Scully by less than a second in the Wednesday twilight time trial, which was staged through the Melbourne CBD.

Pre-race favourite and Orica-GreenEDGE team leader Simon Gerrans finished 11th, but is well-placed at only five seconds off the pace.

Gerrans will achieve a unique Australian triple crown if he wins the five-day tour, having already won last month's national road championship and Adelaide's Tour Down Under.

Garmin-Sharp are the best-equipped outfit in the tour to challenge Orica-GreenEDGE, Australia's only WorldTour team.

"Like everyone says, he's in the form of his life and there's no better bike rider from this side of the world at the moment," Bauer said of Gerrans.

"Obviously he's the man to beat and he has a strong team around him.

"But so do we - we can do exactly the same thing.

"We definitely have a few cards to play."

Bauer is not the main rider for the American-based Garmin-Sharp team, one of three WorldTour lineups at the Victorian race.

Australian Nathan Haas impressed with his fifth at the Tour Down Under and compatriot Rohan Dennis is another Garmin-Sharp rider who could challenge for overall honours.

Bauer was surprised to win the technical 2.5km prologue and the domestique does not expect to contend for the overall title.

"It's a bit of a pity to knock a fellow Kiwi off the top perch, but it might as well be another Kiwi doing it," he said of Scully, who is riding for the New Zealand national team."The whole (Garmin-Sharp) team is here with pretty decent legs.